Underperfoming vs median vs overperforming?

[DPZ2]

Nobody expects perfection in normal mode, but imo underperforming is when you can't be bothered to do the bare minimum and are actually a liability to the rest of the party.

I haven't encountered such players in any instance I've played since I started 8+ years ago. Either I've been lucky or you've been extremely unlucky.

By the way, the OP clarified the instances they wanted to discuss:

Also quick edit, I'm referring only to normal trials/raids/etc, not EX or savage or ultimate where min/max is probably the norm ^^